DETACHMENT MECHANISMS FOR IMPLANTABLE DEVICES
Disclosed herein are detachment mechanisms for vaso-occlusive devices that allow for rapid operator-controlled release of the vaso-occlusive device into the selected site. Also disclosed are vaso-occlusive assemblies comprising these detachment mechanisms and methods of using these detachment mechanisms and vaso-occlusive assemblies.
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This application is a Continuation of U.S. patent application Ser. No. 12/319,255, filed Jan. 5, 2009, which claims the benefit of U.S. Provisional Application No. 61/010,048, filed Jan. 4, 2008, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELDCompositions and methods for implanting devices are described. In particular, detachment mechanisms that change configuration to deploy an implantable device such as an embolic device and assemblies comprising these detachment mechanisms are described.
BACKGROUNDImplantable devices are used for many indications including in the reproductive tract (e.g., uterine artery, fallopian occlusion), biliary implants and/or for peripheral and neurovasculature indications. For example, an aneurysm is a dilation of a blood vessel that poses a risk to health from the potential for rupture; clotting, or dissecting. Rupture of an aneurysm in the brain causes stroke, and rupture of an aneurysm in the abdomen causes shock. Cerebral aneurysms are usually detected in patients as the result of a seizure or hemorrhage and can result in significant morbidity or mortality.
There are a variety of materials and devices which have been used for treatment of peripheral and neurovascular aneurysms, including platinum and stainless steel microcoils, polyvinyl alcohol sponges (Ivalone), and other mechanical devices. For example, vaso-occlusion devices are surgical implements or implants that are placed within the vasculature of the human body, typically via a catheter, either to block the flow of blood through a vessel making up that portion of the vasculature through the formation of an embolus or to form such an embolus within an aneurysm stemming from the vessel. One widely used vaso-occlusive device is a helical wire coil having windings that may be dimensioned to engage the walls of the vessels. (See, e.g., U.S. Pat. No. 4,994,069 to Ritchart et al.). Variations of such devices include polymeric coatings or attached polymeric filaments have also been described. See, e.g., U.S. Pat. Nos. 5,226,911; 5,935,145; 6,033,423; 6,280,457; 6,287,318; and 6,299,627. In addition, coil designs including stretch-resistant members that run through the lumen of the helical vaso-occlusive coil have also been described. See, e.g., U.S. Pat. Nos. 5,582,619; 5,833,705; 5,853,418; 6,004,338; 6,013,084; 6,179,857; and 6,193,728.
Coils have typically been placed at the desired site within the vasculature using a catheter and a pusher. The site is first accessed by the catheter (e.g., small diameter catheters such as those shown in U.S. Pat. Nos. 4,739,768 and 4,813,934). The catheter may be guided to the site through the use of guide-wires (see U.S. Pat. No. 4,884,579) or by flow-directed means such as balloons placed at the distal end of the catheter.
Once the site has been reached, the catheter lumen is cleared by removing the guidewire (if a guidewire has been used), and one or more coils are placed into the proximal open end of the catheter and advanced through the catheter with a pusher. Once the coil reaches the distal end of the catheter, it is discharged from the catheter by the pusher into the vascular site. However, there are concerns when discharging the coil from the distal end of the catheter. For example, the plunging action of the pusher and the coil can make it difficult to position the coil at the site in a controlled manner and with a fine degree of accuracy. Inaccurate placement of the coil can be problematic because once the coil has left the catheter, it is difficult to reposition or retrieve the coil.
Several techniques involving Interlocking Detachable Coils (IDCs), which incorporate mechanical release mechanisms and Guglielmi Detachable Coils (GDCs), which utilize electrolytically actuated release mechanisms, have been developed to enable more accurate placement of coils within a vessel.
Electrolytic coil detachment is disclosed in U.S. Pat. Nos. 5,122,136; 5,354,295; 6,620,152; 6,425,893; and 5,976,131, all to Guglielmi et al., describe electrolytically detachable embolic devices. U.S. Pat. No. 6,623,493 describes vaso-occlusive member assembly with multiple detaching points. U.S. Pat. Nos. 6,589,236 and 6,409,721 describe assemblies containing an electrolytically severable joint. The coil is bonded via a metal-to-metal joint to the distal end of the pusher. The pusher and coil are made of dissimilar metals. The coil-carrying pusher is advanced through the catheter to the site and a small electrical current is passed through the pusher-coil assembly. The current causes the joint between the pusher and the coil to be severed via electrolysis. The pusher may then be retracted leaving the detached coil at an exact position within the vessel. Since no significant mechanical force is applied to the coil during electrolytic detachment, highly accurate coil placement is readily achieved. In addition, the electric current may facilitate thrombus formation at the coil site. The disadvantage of this method is that the electrolytic release of the coil may require a period of time that may inhibit rapid detachment of the coil from the pusher.
There is a need to provide alternative mechanisms for delivering implants, such as embolic coils, that allow for both accurate positioning of the implantable device and rapid detachment from the delivery device.
SUMMARYDisclosed herein are detachment mechanisms for implantable devices, as well as assemblies comprising the detachment mechanisms and implantable devices. Methods of making and using these detachment mechanisms and assemblies are also provided.
In one aspect, provided herein is a detachment mechanism for an implantable device, the implantable device optionally having a lumen therein, the detachment mechanism comprising: at least one material that changes configuration upon application of heat or electrical energy, wherein the change in configuration releases the implantable device, and further wherein if the material extends into the optional lumen of the implantable device, the material directly contacts at least a portion the implantable device defining the lumen. Thus, if the material extends into the lumen of the device, the material is in direct contact with the interior surface of the implantable device. In certain embodiments, the change in configuration comprises a reduction in diameter and/or volume of the material. In other embodiments, the change in configuration comprises an expansion in diameter and/or volume of the material. In still other embodiments, the change in configuration comprises a deflection of the detachment mechanism.
In certain aspects, the detachment mechanisms described herein comprise an electroactive polymer and/or a metal or polymer, for example the electroactive polymer may be layered onto the metal or polymer.
In other aspects, the detachment mechanisms described herein comprise a layered strip of two or more metals of dissimilar thermal coefficients. In certain embodiments, the layered strip is wound into a spiral shape.
In any of the detachment mechanisms described herein, the material may directly contact a source of electric or heat energy. Furthermore, any of the detachment mechanisms described herein may directly engage the vaso-occlusive device. In addition, the detachment mechanism may contact a structure attached to the implantable device.
In another aspect, described herein is a detachment mechanism adapted to detachably engage a vaso-occlusive device, the detachment mechanism comprising an element that changes configuration upon application of electrical current or heat; and means for applying electrical current or heat to the change the configuration of the element.
In yet another aspect, provided herein is a vaso-occlusive assembly comprising a vaso-occlusive device; any of the detachment mechanisms described herein; and a source of electrical current or a heat source in contact with the detachment mechanism. In certain embodiments, the vaso-occlusive device comprises a helically wound vaso-occlusive coil. In still further embodiments, the vaso-occlusive assembly may further comprise a delivery mechanism, for example, a delivery mechanism comprising a stopper element.
In a still further aspect, described herein is a method of at least partially occluding an aneurysm, the method comprising the steps of introducing any of the vaso-occlusive assemblies described herein into the aneurysm, wherein the detachment mechanism engages the vaso-occlusive device; and changing the configuration of the detachment mechanism by applying or removing electrical current or thermal energy such that the detaching mechanism releases the vaso-occlusive device into the aneurysm.
These and other embodiments will readily occur to those of skill in the art in light of the disclosure herein.
Detachment mechanisms for implantable devices, including occlusive (e.g. embolic) devices, and assemblies are described. The detachment mechanisms described herein can be utilized in devices useful in vascular and neurovascular indications and are useful in delivering embolic devices to aneurysms, for example small-diameter, curved or otherwise difficult to access vasculature, for example aneurysms, such as cerebral aneurysms. Methods of making and using these detachments and assemblies comprising these detachments are also aspects of this disclosure.
Currently, the gold-standard method of delivering implantable vaso-occlusive devices is via electrolytic detachment (e.g., GDC coils). While electrolytic detachment solves the drawbacks of earlier mechanical detachments (e.g., the need for the mechanism to be fully inside the catheter in order to remain engaged), electrolytically detachable coils typically require approximately 20-30 seconds detachment times.
The detachment mechanisms described herein that allow for rapid and precise detachment of an implantable device upon application of electrical energy and/or heat. Advantages of the present disclosure include, but are not limited to, (i) the provision of rapidly detachable vaso-occlusive devices; (ii) the provision of mechanically detachable implantable devices that can be extended beyond the catheter tip, thereby allowing for more precise placement of the devices; and (iii) the provision of occlusive devices that minimize the mechanical motion needed to detach the devices.
All publications, patents and patent applications cited herein, whether above or below, are hereby incorporated by reference in their entirety.
It must be noted that, as used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a device comprising “an electroactive polymer” includes devices comprising of two or more such materials or multiple layers of the same electroactive polymer.
The detachment mechanisms described herein allow for rapid release of the vaso-occlusive device from the delivery mechanism. By “rapid” release is meant release in less than 30 seconds, preferably less than 20 seconds and even more preferably between 1 and 15 seconds (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 seconds).
The detachment mechanism may take any desired shape. The detachment mechanism may engage the implantable device by contacting the exterior of the device, directly (e.g., the exterior of the device) or indirectly (e.g., via a structure in contact with the exterior of the device). However, unlike previously described electroactive detachment mechanisms for implantable devices, when the detachment extends into the lumen of the implantable device, it directly engages the interior surface of the device (in either the activated or inactivated state, depending on the properties of the selected materials). The detachment mechanism may be shaped into a ring or spiral structure, for example a spiral wound from a bilayer strip.
In certain aspects, the detachment mechanism comprises an electroactive polymer (EAP) that changes configuration upon the application to electrical energy. Any electroactive polymer can be used, so long as it changes configuration sufficiently in response to application of current. Multiple electroactive polymers may be used, for example, in layers and/or admixed together. Non-limiting examples of suitable electroactive polymers include polypyrrole, nafion, polyanilene, polythiofene and the like. See, e.g., U.S. Pat. No. 6,933,659 and U.S. Patent Publication 20040182704. Electroactive polymers may expand or contract upon activation.
In certain embodiments, the change in configuration of the electroactive polymer(s) is such that, upon the application of electrical current, the polymer's diameter is reduced and, optionally, the axial length is increased. Thus, in the absence of electrical current, the detachment mechanism engages the implantable device within the delivery device. This allows that the delivery-detachment mechanism and vaso-occlusive device to be moved as a unit, even when the implantable device is secured by the electroactive polymer such that extends from the distal end of the delivery mechanism (e.g., delivery catheter or delivery tube). When electricity is applied, the electroactive polymer changes configuration (contracts) such that it no longer secures the device to the delivery device. Accordingly, upon application of electricity to the device is rapidly released into the selected site. In these embodiments, the unactivated electroactive polymer provides a physical compressive grip on the implantable device (e.g., on the exterior or interior surface and/or on a structure affixed to the proximal end of the implantable device) until electrical current is used to active the detachment mechanism. These “fail safe” embodiments minimize the possibility of false or premature detachment of the coil and are advantageous in the event of power failure or accidental interruption so that the embolic remains attached to the delivery wire.
Alternatively, the electroactive polymer may be such that its diameter increases upon application of electrical current. In these embodiments, electrical energy would be applied during deployment and release of the implantable device achieved by stopping the application of electrical current when the implantable device is in the desired position. In embodiments in which the electroactive polymer expands upon the application of electrical energy, the implantable device is positioned within the delivery device and the electroactive polymer is energized to keep the coil in the desired position. The device is then introduced into the access delivery device (e.g., microcatheter). Upon achieving the desired positioning within the aneurysm, the coil is detached by de-energizing the electroactive polymer. These embodiments allow the option of the supplying long lengths of uncut embolic coils to the surgeon. The surgeon can trim the coils to the desired length and mount them on the delivery device to deploy the coils. Delivery devices can be reused multiple times so long as the lumen remains sufficiently clear for insertion.
Detachment mechanisms comprising an electroactive polymer may further comprise metal (e.g., nitinol, stainless steel) and/or polymeric materials. In certain embodiments, the detachment mechanism comprises a super-elastic metal alloy such as nitinol which allows for durability and flexibility. Stainless steel or other metals or alloys can also be used. A portion or all of the detachment mechanism may include one or more surface treatments (coating, machining, microtexturing, etc.). The electroactive polymer is typically coated onto the surface of the metal and/or polymericmaterial.
In other embodiments, the detachment mechanism comprises two or more materials (e.g., metals and/or polymers), typically in layers. Furthermore, in response to thermal or electrical energy, the two or more materials of the detachment mechanism change configuration differently. For example, in certain embodiments, the detachment mechanism comprises a bilayer strip of an electroactive polymer coated onto a metal or polymer substrate. In other embodiments, metals or polymers that respond differently when activated by thermal or electrical energy are employed. The detachment mechanisms described herein also allow for ready retrieval and/or repositioning of vaso-occlusive devices.
Suitable delivery devices include delivery catheters (e.g., microcatheters) with or without delivery tubes (hypotubes) therein. When included, hypotubes may extend the length for the delivery catheter or may be only at the distal region. The delivery devices may include one or more apertures in the side walls that allow for inflow and outflow of electrolytes. See, also, U.S. Provisional Patent Application No. 60/930,436, entitled “Catheters for Electrolytically Detachable Embolic Devices,” filed May 16, 2007. In any of the embodiments described herein, the delivery device may be slotted or spiral cut to reduce bending stiffness while maintaining axial controllability.
In certain embodiments, a braided delivery tube, for example comprising electrodes or heat conducting elements embedded in the sidewalls or extending through the lumen of the delivery tube is employed. Such delivery tubes are adapted to be delivered through conventional catheters (e.g. microcatheters) and, when extended from the distal end of the catheter, allow for even more accurate positioning of the implantable device prior to detachment. In other embodiments, the electrodes (bi-polar or unipolar) extend through the part or all of the lumen of the delivery device.
Furthermore, as noted above, electrical or thermal energy can be provided to the detachment mechanism in any suitable way. The energy source can directly contact the detachment mechanism, for example using a delivery mechanism (e.g., catheter or delivery tube) comprising electrodes or heat conductors in the side-walls. See, e.g., U.S. Pat. Nos. 6,059,779 and 7,020,516. In addition, the electrodes can be attached to a core wire. For example, bi-polar electrodes and/or anodes alone or twisted with a core wire cathode can also be used to supply current to the electroactive polymer. Optionally, the leads may be secured to the core wire; for example via adhesives or via heat-shrink polymer lamination such as PTFE, PEP, PET or urethane. The conductive element may include a polymer jacket/liner to insulate the electrical leads and/or reduce friction during advancement. Alternatively, the detachment mechanism can be activated to change configuration indirectly via a conductive material (e.g., metal) that transmits the electrical or thermal energy to the detachment junction.
It will be apparent that one or more of the electrodes and/or conductive materials that transmit electrical energy to the electroactive polymer may include insulating coatings (e.g., polyimide or the like). For electrical energy, alternating or direct current may be used. Preferably, direct current is used. The amount of current applied will vary according to the application although typically less than 4 volts, preferably around 2 volts is applied to activate the electroactive polymer of the detachment mechanism. Likewise, for materials that change configuration in response to thermal energy, heat can be applied as desired by the operator to change the configuration of the detachment mechanism.
In certain embodiments, the conductor and/or electrodes are distal to the distal end of the delivery mechanism (e.g., tube or coil stopper). As shown in the Figures, the detachment mechanism may be disposed over the conductive surfaces, for example by physical expansion over the electrodes/heat conductors, heat shrinking, conductive adhesives, or the like.
The detachment mechanisms described herein can be adapted to be used with any implantable device, including, but not limited to, vaso-occlusive devices, fallopian tube occlusive devices, uterine implantable devices, biliary implantable devices and the like. The devices may be metal and/or polymeric. Suitable metals and metal alloys include the Platinum Group metals, especially platinum, rhodium, palladium, rhenium, as well as tungsten, gold, silver, tantalum, and alloys of these metals. The core element may also comprise of any of a wide variety of stainless steels. Very desirable materials of construction, from a mechanical point of view, are materials that maintain their shape despite being subjected to high stress including but not limited to “super-elastic alloys” such as nickel/titanium alloys (48-58 atomic % nickel and optionally containing modest amounts of iron); copper/zinc alloys (38-42 weight % zinc); copper/zinc alloys containing 1-10 weight % of beryllium, silicon, tin, aluminum, or gallium; or nickel/aluminum alloys (36-38 atomic % aluminum). Particularly preferred are the alloys described in U.S. Pat. Nos. 3,174,851; 3,351,463; and 3,753,700. Especially preferred is the titanium/nickel alloy known as “nitinol.”
The detachment mechanisms described herein may be used with implantable devices of any structure, for example, devices of tubular structures, for examples, braids, coils, combination braid and coils and the like. Thus, although depicted in the Figures described below as a vaso-occlusive coil, the device may be of a variety of shapes or configuration including, but not limited to, braids, knits, woven structures, tubes (e.g., perforated or slotted tubes), cables, injection-molded devices and the like. See, e.g., U.S. Pat. No. 6,533,801 and International Patent Publication WO 02/096273. The implantable device may change shape upon deployment, for example change from a constrained linear form to a relaxed, three-dimensional (secondary) configuration. See, also, U.S. Pat. No. 6,280,457. In a preferred embodiment, the core element comprises a metal wire wound into a primary helical shape. The core element may be, but is not necessarily, subjected to a heating step to set the wire into the primary shape. Methods of making vaso-occlusive coils having a linear helical shape and/or a different three-dimensional (secondary) configuration are known in. the art and described in detail in the documents cited above, for example in U.S. Pat. No. 6,280,457. Thus, it is further within the scope of this disclosure that the vaso-occlusive device as a whole or elements thereof comprise secondary shapes or structures that differ from the linear coil shapes depicted in the Figures, for examples, spheres, ellipses, spirals, ovoids, figure-8 shapes, etc. The devices described herein may be self-forming in that they assume the secondary configuration upon deployment into an aneurysm. Alternatively, the devices may assume their secondary configurations under certain conditions (e.g., change in temperature, application of energy, etc.).
It will be apparent that the structure may be secured to the coil at any location and by any suitable means, for example, gluing, soldering, welding, etc. Furthermore, any structural element can be used, including, for example, ball, rings, hooks and the like.
When the delivery device comprises a marker or stopper coil, it can be of the same or different diameter than the implantable device. In certain embodiments, the stopper coil has a slightly smaller inner diameter than the implantable coil such that when the coils are axially aligned they contact each other but create a ridged area at their junctions. In the engaged coils were of the same diameter.
In embodiments in which the electroactive polymer expands upon the application of electrical energy, the implantable device is positioned within the delivery device and the electroactive polymer is energized to keep the coil in the desired position. For example, in the design shown in
The layered strip may include an electroactive polymer which expands or contracts upon application of electrical energy. Alternatively, the strip may be comprised of two or more dissimilar metals having disparate thermal expansion coefficients such that, upon a change in temperature, they change shape with relation to the other(s), i.e. deflect, bend, and/or expand. It will be apparent that when an electroactive polymer is used in these strips, the detachment mechanism is operably liked to a source of electrical current. Likewise, if dissimilar metals are used, the strips are operably connected to a heat source.
As noted above, in any of the embodiments described herein, there may be one or more layers of electroactive polymer. Furthermore, the electroactive polymer can be deposited onto any substrate, for example a metal (e.g., nitinol) or polymer (e.g., urethane). The electroactive polymer can be deposited by any means, for example by coating, gluing, and the like.
In certain embodiments, the assemblies described herein further comprise an element (e.g., band) around the proximal end of the implantable device and/or delivery mechanism to help maintain contact with the electroactive polymer. Non-limiting examples of such elements include thin-walled metal (e.g., stainless steel, nitinol, and/or platinum alloys) and/or polymer (PEEK, PET, polyimide) bands. Alternatively, a region of the coil (e.g., winds of the coil) can be soldered or welded together.
Although shown in
The T-bar may not be a single T in that any number of posts can be used, for example, 1, 2, 3, 4, 5 or even more posts can be used. In a preferred embodiment, the T-bar includes 2 posts.
Furthermore, the T-bar and structures (e.g., fin-like structures) it engages maybe made of any material (e.g., polymer and/or metal). In certain embodiments, the fin-like structures comprise platinum. In other embodiments, the T-bar comprises platinum, nitinol, stainless steel and/or polyimide and can be electrochemically etched or formed by bending segments of wire. The fin-like structures or T-bar may be attached to the implant by any suitable means, including but not limited to soldering, welding, adhesives, etc. An optional collar may be placed around the finds and/or T-bar to reduce or prevent pivoting of the fins about the T-bar structure.
In any of the embodiments described herein, the electroactive polymer 20 can be disposed directly on the delivery device or on a flexible substrate 38, for example a flexible substrate that deflects when the electroactive polymer 20 disposed therein is activated/unactivated by electrical current (see, e.g., description above regarding
The devices described herein are often introduced into a selected site using the procedure outlined below. This procedure may be used in treating a variety of maladies. For instance in the treatment of an aneurysm, the aneurysm itself will be filled (partially or fully) with the compositions described herein.
Conventional catheter insertion and navigational techniques involving guidewires or flow-directed devices may be used to access the site with a catheter. The mechanism will such as to be capable of being advanced entirely through the catheter to place vaso-occlusive device at the target site but yet with a sufficient portion of the distal end of the delivery mechanism protruding from the distal end of the catheter to enable detachment of the implantable vaso-occlusive device. For use in peripheral or neural surgeries, the delivery mechanism will normally be about 100-200 cm in length, more normally 130-180 cm in length. The diameter of the delivery mechanism is usually in the range of 0.25 to about 0.90 mm. Briefly, occlusive devices (and/or additional components) described herein are typically loaded into a carrier for introduction into the delivery catheter and introduced to the chosen site using the procedure outlined below. This procedure may be used in treating a variety of maladies. For instance, in treatment of an aneurysm, the aneurysm itself may be filled with the embolics (e.g. vaso-occlusive members and/or liquid embolics and bioactive materials) which cause formation of an emboli and, at some later time, is at least partially replaced by neovascularized collagenous material formed around the implanted vaso-occlusive devices.
A selected site is reached through the vascular system using a collection of specifically chosen catheters and/or guide wires. It is clear that should the site be in a remote site, e.g., in the brain, methods of reaching this site are somewhat limited. One widely accepted procedure is found in U.S. Pat. No. 4,994,069 to Ritchart, et al. It utilizes a fine endovascular catheter such as is found in U.S. Pat. No. 4,739,768, to Engelson. First of all, a large catheter is introduced through an entry site in the vasculature. Typically, this would be through a femoral artery in the groin. Other entry sites sometimes chosen are found in the neck and are in general well known by physicians who practice this type of medicine. Once the introducer is in place, a guiding catheter is then used to provide a safe passageway from the entry site to a region near the site to be treated. For instance, in treating a site in the human brain, a guiding catheter would be chosen which would extend from the entry site at the femoral artery, up through the large arteries extending to the heart, around the heart through the aortic arch, and downstream through one of the arteries extending from the upper side of the aorta. A guidewire and neurovascular catheter such as that described in the Engelson patent are then placed through the guiding catheter. Once the distal end of the catheter is positioned at the site, often by locating its distal end through the use of radiopaque marker material and fluoroscopy, the catheter is cleared and/or flushed with an electrolyte solution.
Once the selected site has been reached, the vaso-occlusive device is extruded using a pusher-detachment mechanism as described herein and released in the desired position of the selected site.
Modifications of the procedure and. vaso-occlusive devices described above, and the methods of using them in keeping with this disclosure will be apparent to those having skill in this mechanical and surgical art. These variations are intended to be within the scope of the claims that follow.
Claims
1-18. (canceled)
19. A detachment mechanism for an implantable device, comprising:
- an implantable device that includes a structure extending therefrom;
- a delivery device that includes an electroactive polymer configured to move from an unexpanded configuration to an expanded configuration, wherein the delivery device reversibly engages at least a portion of the structure of the implantable device when in the unexpanded configuration.
20. The detachment mechanism of claim 19, wherein the electroactive polymer moves from an unexpanded configuration to an expanded configuration upon application of energy.
21. The detachment mechanism of claim 20, wherein the energy is heat.
22. The detachment mechanism of claim 20, wherein the energy is electrical energy.
23. The detachment mechanism of claim 19, further comprising an energy source, wherein the electroactive polymer is in direct contact with the energy source.
24. The detachment mechanism of claim 19, further comprising an energy source, wherein the electroactive polymer is not in direct contact with the energy source.
25. The detachment mechanism of claim 19, wherein the electroactive polymer does not substantially engage the structure of the implantable device when in the unexpanded configuration.
26. The detachment mechanism of claim 19, wherein the implantable device is a vaso-occlusive coil.
27. A detachment mechanism for an implantable device, comprising:
- an implantable device that includes an structure extending therefrom;
- a delivery device that includes an electroactive polymer configured to move from an expanded configuration to an unexpanded configuration, wherein the delivery device reversibly engages at least a portion of the structure when the implantable device is in the expanded configuration.
28. The detachment mechanism of claim 27, wherein the electroactive polymer moves from an expanded configuration to an unexpanded configuration upon application of energy.
29. The detachment mechanism of claim 28, wherein the energy is heat.
30. The detachment mechanism of claim 28, wherein the energy is electrical energy.
31. The detachment mechanism of claim 27, further comprising an energy source, wherein the electroactive polymer is in direct contact with the energy source.
32. The detachment mechanism of claim 27 further comprising an energy source, wherein the electroactive polymer is not in direct contact with the energy source.
33. The detachment mechanism of claim 27 wherein the electroactive polymer does not substantially engage the structure of the implantable device when in the expanded configuration.
34. The detachment mechanism of claim 27, wherein the implantable device is a vaso-occlusive coil.
35. A method of delivering an implantable device, the method comprising:
- introducing a medical device comprising a detachment mechanism according to claim 1 into the vasculature of a patient;
- applying energy such that the electroactive polymer moves from an unexpanded configuration to an expanded configuration thereby releasing the implantable device; and
- removing the medical device from the patient.
36. A method of delivering an implantable device, the method comprising:
- introducing a medical device comprising a detachment mechanism according to claim 9 into the vasculature of a patient;
- applying energy such that the electroactive polymer moves from an expanded configuration to an unexpanded configuration thereby releasing the implantable device; and
- removing the medical device from the patient.
37. The method of claim 35, wherein the implantable device at least partially occludes an aneurysm within the vasculature of the patient.
38. The method of claim 36, wherein the implantable device at least partially occludes an aneurysm within the vasculature of the patient.
Type: Application
Filed: Feb 23, 2015
Publication Date: Dec 14, 2017
Patent Grant number: 10478192
Applicant: Boston Scientific Scimed, Inc. (Maple Grove, MN)
Inventors: Clifford TEOH (Los Altos, CA), Michael Williams (Oakland, CA), Gregory E. Mirigian (Dublin, CA), Kirsten Carroll (San Francisco, CA), James M. Anderson (Fridley, MN), Jay Rassat (Buffalo, MN), Benjamin Arcand (Minneapolis, MN), Derek Sutermeister (Eden Prairie, MN)
Application Number: 14/629,392